1. Field of the Invention
The present invention relates generally to the reduction of ocular discomfort and vision problems associated with sustained close-range viewing, and more specifically to a system kit and method for use by a viewer to reduce eyestrain associated with sustained close-range viewing.
2. Background of the Invention
The use of computers in a variety of applications such as word processing, accounting, desk-top publishing, computer-aided drafting, engineering, programming, spreadsheets, game-playing and the like is now widespread. These applications demand sustained use of the computer for more hours than ever before and have raised concerns about undesirable health effects to the user. As computer usage in the workplace increases due to advances such as electronic mail, computer ordering/billing, Internet advertising, computer faxing, and on-line services, reducing an employee's computer-related fatigue plays an increasingly vital role in enhancing productivity.
Many computer users complain of ocular discomfort and vision problems, muscular tension, joint stress and strain, and neck soreness. The ocular discomfort and vision problems are generally referred to as Computer Vision Syndrome (CVS), while the muscle and joint (musculoskeletal) disorders are generally referred to as repetitive stress disorders. Repetitive stress injuries usually occur by performing repetitive movements or by being required to remain in a specific position for long periods of time.
While most health surveys for computer users clearly show that the majority of health related complaints are visually oriented, almost all public and professional attention has been directed towards the musculoskeletal disorders, such as carpal tunnel syndrome and neck tension disorder. According to a survey conducted by the National Institute for Occupational Safety and Health (NIOSH), about 88% of the people who work at computers for more than three hours a day suffer from symptoms of eyestrain. The same survey conducted by the NIOSH states that while up to 88% of computer users experience CVS, 22% of computer users experience repetitive stress disorders. It has been estimated that it costs $1.9 billion a year for U.S. companies and employees to diagnose and treat CVS.
Moreover, numerous ergonomic products are currently available to reduce or minimize the discomfort associated with prolonged computer use to prevent musculoskeletal disorders. These products are primarily directed to preventing carpal tunnel syndrome and muscle fatigue. However, these products do not provide prevention of eyestrain. Accordingly, there is a continuing need in the industry for a system for reducing eyestrain caused by prolonged computer use.
It is well known that ocular discomfort and vision problems, such as eyestrain, burning sensations in the eyes, headaches, fatigue, blurring of vision, decreased productivity, and the progressive increase in one's level of nearsightedness result from the prolonged viewing of computer monitor screens. Particularly, severe operator eyestrain results when the operator is required to view the monitor screen for extended periods of time while simultaneously operating a computer keyboard and periodically viewing various documents.
Vision problems and discomfort associated with prolonged viewing appear to be caused by strain of the eye muscles of the viewer attempting to maintain a sustained focus and to converge the eyes to the near point image on the screen. It has been determined that when an individual looks at a computer monitor screen, the natural position of the eye muscles directs the eyes almost straight ahead for distance vision. Therefore, in order to view a computer monitor, at the normal viewing distance of from 18-30 inches, the eye muscles strain as we focus and converge the eyes, then sustain this focus and convergence. When we gaze downward at about an angle of 20.degree.-30.degree., the eyes will converge automatically for near vision.
In the course of developing the system kit and technique of the instant invention, applicant has formulated a new and unique theory which is believed to explain the cause of CVS. It is believed that there is a neurological "battle" occurring, which causes the eye muscles to fight against each other, and the resulting muscle spasm leads to problems relating to CVS. When we look at a monitor, we see light areas where the letters are located and dark areas everywhere else on the screen. Projecting these light and dark areas back to the retina, light causes the pupil to constrict, or get smaller, while dark areas cause the pupil to dilate, or get bigger. These opposing signals cause the opposing muscles, the dilator and the sphincter, to work at the same time, causing a muscle spasm which leads to eyestrain and resulting vision problems. As the computer user looks away from the monitor, the spasm prevents the eye from relaxing the focus and see in the distance, momentarily causing blurred vision. For a while, about 6-12 months, you can get the spasm to relax by closing the eyes and relaxing for a few moments. Eventually, however, the focus will not relax and the computer user becomes more nearsighted. It will be appreciated that the foregoing problems are generally unrecognized, especially when working with video display terminals.
The constant glare from the computer screen also often results in eyestrain, which leads to severe headaches and other discomforts. Reflections on the computer screen from overhead lights also contribute to eyestrain and fatigue. In addition, background and overhead lighting can produce glare in the computer operator's eyes which makes it difficult for the operator to focus on the computer monitor.
It has been proposed to reduce the level of background and overhead room lighting in order to reduce eyestrain. However, decreasing the surrounding room lighting is often not possible due to other workers, and is generally not beneficial as a computer user must still be able to look to and see other items and documents near the computer. It has also been proposed to increase the brightness and/or contrast settings on the monitor in order to overcome the effects of light striking the monitor surface. Such techniques are generally not favorable, however, because in addition to dramatically increasing the strain and fatigue on the user's eyes, the computer monitor may be damaged by burn-in, a common form of display damage.
In addition to eyestrain caused by attempting to focus on a computer monitor, persons using bifocals are forced to tilt their heads up toward the ceiling in order to view the screen through their bifocal segment. Tilting the head is uncomfortable and causes neckstrain, backache and fatigue.
Various types of optical apparatus have been proposed to alleviate or reduce such eyestrain by placing optical devices between the operator and the computer screen. For example U.S. Pat. No. 4,712,870 to Robinson describes a magnifying Fresnell lens which is interposed between the monitor and the operator to magnify the monitor screen image. Another such Fresnell magnifying lens and glare reduction system is disclosed in U.S. Pat. No. 4,577,928 to Brown. An anti-glare device comprising a filter screen for attachment to a CRT computer terminal display is disclosed in U.S. Pat. No. 4,253,737 to Thomsen. An adjustable lens holder for various magnifier, color tinting or anti-glare lenses is disclosed in the U.S. Pat. No. 4,529,268 to Brown.
Numerous anti-glare shields and eye shades have also been proposed for various purposes. For example, various eye shields have been proposed for drivers and pilots to reduce the glare from the sun or lights. Other eye shields have been proposed which serve as blinders to avoid distraction during various activities and for training exercises. Examples of these types of eye shields are disclosed in U.S. Pat. Nos. 2,933,734; 3,330,051; 3,308,498; 3,225,459 and 5,261,124. These devices do not provide adequate protection from glare and reflection from incidental light, as well as the glare from the computer terminal. Furthermore, these devices are typically bulky and uncomfortable to wear.
Although image magnification and glare reduction devices may provide certain benefits, the principal cause of computer operator eyestrain remains that the operator's eyes must converge and focus on the images carried by the CRT computer monitor screen. If the degree of focussing required to bring the screen into focus can be reduced, the resultant eyestrain is significantly reduced.
Another general eye discomfort of computer users is generally related to "dry eye". Recent studies by the medical profession have resulted in a breakthrough with respect to understanding the problem. Medical investigators have determined that a computer user staring at a display terminal blinks at a rate which is significantly below the norm for that individual. For example, the blink rate for computer users can drop from a normal of 12-25 times per minute to 3-5 times per minute. This reduction in the rate at which a person blinks causes a corresponding reduction in the frequency at which the eye is cleansed and bathed by secretions from the glands. Some people aggravate the problem with poor computer position, such as having their computer screens sit above their head. When people look up at a computer screen, it forces their eye lids to open wider, exposing more surface area to the drying air. The foregoing lead to a dry eye syndrome manifested as discomfort, irritation and fatigue. In extreme cases, the irritation can lead to more serious problems affecting the health of the eyes. One factor leading to the reduced blink syndrome is that a video display terminal changes on a micro level as single letters or numbers are added to the screen by an operator. This creates a gradual or micro change to the visual field which will not stimulate a blink response. Furthermore, as we blink, we interrupt our point of gaze, causing the need to refocus and redirect our gaze after each blink, inducing eyestrain. In order to avoid this, we stare, causing dryness.
The present invention overcomes many of the disadvantages inherent in conventional methods and apparatuses for reducing ocular discomfort and vision problems associated with sustained close-range viewing.